Heat wave continues to bake California and threaten power shutoffs

 A record-breaking heat wave has baked the West for days -- fueling destructive wildfires and threatening rolling power shutoffs in California -- and it could last even longer due to the effects of a hurricane forming along Mexico's Pacific Coast.

Sacramento hit 116 degrees Tuesday, the hottest day on record for the state capital, according to the National Weather Service. It even beat high temperatures this year for Phoenix (115) and Las Vegas (112). It was only nine degrees cooler than Death Valley's high.

Cal ISO has extended a flex alert for Wednesday from 4 p.m.-9 p.m. People are urged, early in the day, to precool their homes, use window coverings, and charge EVs and personal and medical devices. Just after 2 p.m., Cal ISO issued an Energy Emergency Alert (EEA) 2. After that comes an EEA 3. Then, after that comes rolling blackouts. 

Records were also broken all over the Bay Area, with some cities shattering previous daily records by more than 10 degrees.

"We are now heading into the worst part of it -- the risk of outages is real," California Gov. Gavin Newsom said in a tweet Tuesday, adding that the temperatures in the state are "unprecedented."

The heat wave will be the hottest and longest on record for California for September, he said.

California residents have for days been urged to set thermostats to 78 degrees or higher -- despite the heat -- as well as avoid using major appliances, and turn off all unnecessary lights between the hours of 4 p.m. and 9 p.m.

Pacific Gas & Electric, the nation's largest utility, has notified about 525,000 customers to prepare for potential rotating outages.

The California Independent System Operator -- which manages most of the state's power grid -- issued an emergency alert for Tuesday evening, saying grid conditions had worsened and energy supplies were insufficient to cover demand. The alert was lifted hours later and the operator thanked "consumer conservation."

While relief was expected Thursday, the oppressive heat is now expected to last through at least Friday.

Hurricane Kay will bring strong rains and high winds to the Mexican coast, but far from its center, the storm will also dictate the weather pattern for Southern California.

Kay will still be about 220 miles south of San Diego on Friday, according to the National Weather Service in Los Angeles, but the flow around the storm will bring easterly winds to the area, which could bring extreme heat all the way down to the beaches.

The weather service in San Diego extended the excessive heat warning for the region through Friday to account for the possibility of high temperatures well into the 90s to 100 reaching the coast.

Scorching hot temperatures shatter records

Numerous heat records have been set across the West, according to the weather service.

In California, San Francisco airport hit 97 degrees Monday, breaking a daily record. Salinas hit 103 degrees, shattering the previous record of 92 degrees set in 2004. Livermore hit a record high of 116.

Salt Lake City hit 104 Monday, the hottest September day on record and also the 32nd day this year with temperatures reaching at least 100 degrees, beating the previous record by 11 days.

Temperatures in Billings, Montana, reached 100 degrees Monday, which tied a previous record. This was the first time Billings has hit 100 degrees twice in the same September.

Scientists say searing heat is part of a global pattern of rising temperatures, and climate change is making heat waves hotter and more frequent.

Greenhouse gas emissions from human activities have heated the planet by about 1.2 Celsius since pre-industrial times and that warmer baseline means higher temperatures can be reached during extreme heat events, scientists say.

Wildfires ignited throughout the West

The hot and dry conditions also mean that fires will spread more quickly, rage more intensely and burn for longer.

Several destructive wildfires erupted over the past week, with at least four people dying in two California blazes that also burned homes and thousands of acres of land.

The fires, burning simultaneously in parched drought-stricken lands, have choked the hot atmosphere with smoke, bringing unhealthy air quality to parts of the Western states.

The thick smoke, billowing from numerous wildfires, is visible from space, according to images released by the National Oceanic and Atmospheric Administration

The fires have also displaced thousands of residents as the flames advanced on communities, slashing through dry vegetation, and burning homes and cars.

Two people were killed as the fast-moving Fairview Fire swelled rapidly over parched vegetation in Southern California on Monday, forcing hundreds of residents to flee. The blaze had burned 4,500 acres by Tuesday and was 5% contained.

To the north, in Siskiyou County, two women, ages 66 and 73, died in the Mill Fire that burned 4,263 acres and destroyed 98 structures as of Tuesday night.

Nearby, the Mountain Fire, also burning in Siskiyou County, tore through 11,690 acres.

In Oregon, the Cedar Creek Fire had consumed 17,625 acres in five days after being sparked by lightning, authorities said.

Meanwhile, the Ross Fork Fire in Idaho that ignited in mid-August continues to burn and has engulfed 26,020 acres. Firefighters had it 2% contained Tuesday.

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